The present invention relates to a process and to a machine for manufacturing a tubular element, for example for use in forming boxes, such as cardboard bell boxes which are used for packaging in the perfume industry. It is possible for the tubular element to have any cross-section, that is to say round, oval, square or polygonal, with sharp or rounded corners, and so on, to have any desired height, that is to say tall or short, and to have a single or multiple thickness of cardboard, for example a double thickness, over all or part of its height.
If a double thickness of cardboard is provided over the greater part of the height of the tubular element, leaving a margin of single thickness, the latter makes it possible to complete the formation of the box with a double base.
Hitherto, the automatic manufacture of boxes on a machine has not made it possible to produce boxes of which the height is large, relative to the dimensions of the base, as in the case of bell boxes. It is for this reason that these bell boxes are generally constructed by hand.